Our addiction to Korean cinema intensified this year with this gorgeous movie from Park Chan-wook, who has recently pivoted to luxurious suspense thrillers, away from the gonzo-ultraviolent revenge pictures that made his name.

It is a sensational black-widow noir, featuring a cop called Hae-joon (Park Hae-il) who is investigating the mysterious death of a man whose body is found at the bottom of a well-known climbing rock. Did he fall? Was he pushed? In pursuing the case, Hae-joon finds himself falling for this man’s widow, delectably played by the Chinese star Tang Wei – feelings that may well be getting more intense the more he suspects that she is guilty.

And in every corner of this detective’s life he finds a variation on a single, painful question: at what point do you decide your marriage isn’t working? At what stage do you cut your losses on everything you have built so far? When do you know that you are in love and this is the one? When, in fact, do you make the decision to leave?

Tang Wei is superbly charismatic, bringing a live-wire energy and chemistry to her relationship with her leading man: sexually intense but reserved, capable, strong, intimidatingly smart but bearing a poignant and unacknowledged emotional wound.

There is something very Hitchcockian (though without being an obvious homage) in the film’s tension, its intrigue, its showstopping emotional confrontations, its ingenious use of the mobile phone technology that is so often a narrative stumbling block in thrillers, and its setpieces, including a rooftop chase. The plot twists are very manipulative: Decision to Leave keeps you off-balance, hitting you with new developments and unfamiliar characters. A gripping film.